Detection and control of microorganisms are important in many fields including health care, environmental regulation, bio-warfare, pathogen identification, food and drug testing and in a variety of industrial systems. In industry, presence of undesirable microorganisms decreases the efficiency of operating equipment and ultimately increases the cost of associated goods or services. Furthermore, since microorganisms multiply rapidly, the presence of microbial activity also causes health risks to the public. There is an increasing concern with pathogenic organisms infecting water and process and creating increased human, animal and environmental health risk.
In cooling towers, for example, water borne pathogenic microorganisms, such as Legionella sp. may be present. If not properly treated with preferred biocides, aerosolized particles containing the microorganisms can create extreme health concerns from inhalation of the aerosolized microorganisms leading to disease such as Pontiac fever or the sometimes fatal Legionnaire's disease caused by Legionella pneumophila. Detection of this and other microorganisms is difficult, especially in the case of open recirculation water systems such as cooling towers because low concentration represent serious health risk and large water volumes must be concentrated into smaller sample volumes in order to perform the desired analytical test and obtain accurate and reproducible results.